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Abstract: Instances of sexual size dimorphism (SSD) provide the context for rigorous tests of biological rules of size evolution, such as Cope’s rule (phyletic size increase), Rensch’s rule (allometric patterns of male and female size), as well as male and female body size optima. In certain spider groups, such as the golden orbweavers (Nephilidae), extreme female-biased SSD (eSSD, female:male body length 2) is the norm. Nephilid genera construct webs of exaggerated proportions, which can be aerial, arboricolous, or intermediate (hybrid). First, we established the backbone phylogeny of Nephilidae using 367 anchored hybrid enrichment markers, then combined these data with classical markers for a reference species-level phylogeny. Second, we used the phylogeny to test Cope and Rensch’s rules, sex specific size optima, and the coevolution of web size, type, and features with female and male body size and their ratio, SSD. Male, but not female, size increases significantly over time, and refutes Cope’s rule. Allometric analyses reject the converse, Rensch’s rule. Male and female body sizes are uncorrelated. Female size evolution is random, but males evolve toward an optimum size (3.2–4.9 mm). Overall, female body size correlates positively with absolute web size. However, intermediate sized females build the largest webs (of the hybrid type), giant female Nephila and Trichonephila build smaller webs (of the aerial type), and the smallest females build the smallest webs (of the arboricolous type). We propose taxonomic changes based on the criteria of clade age, monophyly and exclusivity, classification information content, and diagnosability. Spider families, as currently defined, tend to be between 37 million years old and 98 million years old, and Nephilidae is estimated at 133 Ma (97–146), thus deserving family status. We, therefore, resurrect the family Nephilidae Simon 1894 that contains Clitaetra Simon 1889, the Cretaceous GeratonephilaPoinar and Buckley (2012), Herennia Thorell 1877, IndoetraKuntner 2006, new rank, Nephila Leach 1815, Nephilengys L. Koch 1872, Nephilingis Kuntner 2013, Palaeonephila Wunderlich 2004 from Tertiary Baltic amber, and TrichonephilaDahl 1911, new rank. We propose the new clade Orbipurae to contain Araneidae Clerck 1757, Phonognathidae Simon 1894, new rank, and Nephilidae. Nephilid female gigantism is a phylogenetically ancient phenotype (over 100 Ma), as is eSSD, though their magnitudes vary by lineage.
Keywords: spiders, evolution of sexual size dimorphism, golden orbweavers, analyses
Published in DiRROS: 24.07.2024; Views: 459; Downloads: 218
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Abstract: The adaptation of autochthonous olive varieties to local soil and climatic conditions can lead to a unique chemical composition and characteristics of olive oils that may differ from the generally accepted quality standards set out in the International Olive Oil Council strategy documents and EU regulations. Therefore, the fatty acid composition, biophenol, tocopherol, sterol and triterpenic dialcohol content and composition of the autochthonous Slovenian olive varieties ‘Buga’, ‘Crnica’ ˇ and ‘Drobnica’ were studied for a three-year period with the aim of valorising the characteristics of the three olive varieties. Standardised and accredited analytical methods in accordance with SIST EN ISO/IEC 17025:2017 were applied. The results of the investigation showed that the highest average amount of oleic acid (75.75%) was found in the oils of the ‘Crnica’ variety, followed by the ‘Drobnica’ ˇ (72.06%) and the ‘Buga’ (68.73%). All three varieties are a good source of total biophenols (‘Buga’ 616 mg/kg, ‘Drobnica’ 569 mg/kg and ‘Crnica’ 427 mg/kg) and ˇ α-tocopherol (‘Buga’ 378 mg/kg, ‘Drobnica’ 279 mg/kg, and ‘Crnica’ 243 mg/kg). ‘Buga’ and ‘Drobnica’ are characterised by high ˇ amounts of total sterols, 2468 mg/kg and 2391 mg/kg, respectively, while ‘Crnica’ oils, in comparison, ˇ showed a lower average value of total sterols (1351 mg/kg). Due to their exceptional chemical composition, ‘Buga’, ‘Crnica’ and ‘Drobnica’ show great potential for the further cultivation and ˇ valorisation of traditional olive oil production in the region, thus contributing to the preservation of biodiversity and local traditions. The quality parameters of olive oil from the autochthonous Slovenian olive varieties ‘Buga’, ‘Crnica’ and ‘Drobnica’ also fulfil the limits for extra virgin olive oil ˇ according to the Commission Delegated Regulation (EU) 2022/2104, despite local climatic influences. However, accelerated growth due to climatic changes affecting early harvest can lead to them falling outside these limits, which was observed in particular for the ‘Buga’ variety in terms of the linoleic acid content. This study emphasises the importance of timing the harvest to achieve optimum maturity and meet EU quality standards, taking into account the genetic makeup of the varieties and their response to the current climatic conditions.
Keywords: olive, autochthonous Slovenian olive varieties, olive oil, bioactive compounds, chemistry, characterisation
Published in DiRROS: 24.07.2024; Views: 234; Downloads: 125
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Abstract: The longhorned beetle Arhopalus rusticus (Coleoptera: Cerambycidae, Spondylinae) is a common species in conifer forests of the Northern Hemisphere, but with global trade, it has invaded and become established in New Zealand, Australia, and South America. Arhopalus rusticus is a suspected vector of the phytopathogenic nematode, Bursaphelenchus xylophilus, the causative agent of pine wilt disease, which is a major threat to pine forests worldwide. Here, we report the identification of a volatile, male-produced aggregation-sex pheromone for this species. Headspace odours from males contained a major male-specific compound, identified as (2 S, 5E)-6,10-dimethyl-5,9-undecadien-2-ol (common name (S)-fuscumol), and a minor component (E)-6,10-dimethyl-5,9-undecadien-2-one (geranylacetone). Both compounds are known pheromone components for species in the same subfamily. In field trials in its native range in Slovenia, (S)-fuscumol was significantly more attractive to beetles of both sexes, than racemic fuscumol and a blend of host plant volatiles commonly used as an attractant for this species. Fuscumol-baited traps also caught significant numbers of another spondylidine species, Spondylis buprestoides (L.), and a rare click beetle, Stenagostus rufus (De Geer). The pheromone can be exploited as a cost-effective and environmentally safe tool for detection and monitoring of this invasive species at ports of entry, and for monitoring the beetle’s distribution and population trends in both endemic and invasive populations.
Keywords: pheromones, invasive organisms
Published in DiRROS: 24.07.2024; Views: 258; Downloads: 132
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Abstract: Temperature has strong effects on species composition and traits. These effects can differ within and between species groups. Thermoregulation and mobility are traits which can be strongly affected by altitudinal distribution. Our aim was to investigate the influence of altitude on the species richness, abundance and composition of species groups with different trophic, thermoregulatory and mobility traits. Carabids (Coleoptera; Carabidae), hoverflies (Diptera: Syrphidae) and birds (Aves: Passeriformes) were counted in three altitudinal belts with a total elevation difference of 700 m (from 300 m to 1000 m a.s.l.) in the same habitat type (non-fragmented temperate montane mixed beech and fir forest). We found that endotherms and more mobile species (i.e. birds) had a smaller turnover than ectotherms (i.e. hoverflies) and less mobile species (i.e. carabids), from which we can predict that the former species will undergo a less extreme shift than the latter in global warming scenarios. Species turnover across the altitudinal gradient increased from birds to hoverflies to carabid beetles. The effect of altitude on phenology was different between the studied ectotherm species groups (carabids and hoverflies). Hoverflies experience a phenological delay of species richness and abundance at higher altitudes in spring, but not at the end of summer, which implies that hoverfly phenology is affected by a change in temperature, while carabid beetle abundance exhibited a delay in phenology in summer at higher altitudes. We suggest that species that are expected to be most affected by climate change, such as ectotherms and species with poor dispersal ability should be prioritised as the best indicators for monitoring and conservation management purposes.
Keywords: climate change, Carabidae, Syrphidae, Aves, altitudinal gradient, species assemblage
Published in DiRROS: 24.07.2024; Views: 233; Downloads: 168
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Published in DiRROS: 24.07.2024; Views: 265; Downloads: 199
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